Why do programmers choose to write their own code instead of using code that is already available online?

Read also:

• When a dog smells another dog’s poo or wee, do they then remember that scent for when they smell it again, or even further know which dog they are smelling if they know the dog?
• What’s a historical event you wish more people talked about?
• Why cant I sleep? When I'm about to fall asleep, I get excited that im about to sleep, causing me to wake up again. It repeats till my sleepiness is gone. I tried taking melatonin and not using my phone, but I end upawake for hours.
• What is love?
• Acting NASA Administrator Janet Petro ‘Embrace The Challenge’ Update June 6, 2025 - NASA Watch
• What story do you have involving a public restroom?
• Why do women stubbornly refuse to let men lead, even though they are attracted to the man, and the man both loves and desires them? Why do they get angry and blame the man when he gets fed up and walks away, when it's entirely their own fault?
• Why cant school buses ditch kids who are late to the bus at the school? Like on the way home, if a kid is late when all the others arrived to the bus on time, why cant they leave the late kid behind since its not fair to the on time kids to wait?
• Can you show pictures of your penis, big or small?
• What is the most popular song that includes the word "you"? Are there any other songs that use "you" multiple times?